Guangzhou police said via its microblog account it had opened an investigation into the death of a foreign national on Monday. It said officers in Yuexiu district had been called because of a fight between a foreigner and an electric bicycle driver over a fare dispute.

Police took both men back to the police station to investigate, it said. But hours later the foreigner suddenly became unconscious and died despite officers summoning medical help.

In a separate post, the police said foreigners had blocked traffic on Guangyuan West Road – where the fight broke out – on Tuesday afternoon but were dispersed by officers.

They appealed to expatriates living in China to "abide by Chinese laws, not harm public interests or disrupt public order" and said police would investigate the death in strict accordance with the law.

One picture posted on Sina's Weibo microblog showed a man carrying a cardboard placard reading "Give us the dead body" in English and Chinese.

Protests by foreign nationals residing in the country are rare in China. More than 100 demonstrators surrounded a police station in Guangzhou in 2009 after a Nigerian man died during an immigration raid. Reports said he had jumped from a second-floor window as police mounted surprise passport checks.